Mental Maths: Multiply and Divide Masterclass

Mental Maths: Multiply and Divide Masterclass

Year 6 Mathematics NSW Curriculum Lesson 1 of 3: Mastering Mental Maths Strategies

WALT (We Are Learning To)

Apply mental computation strategies to multiply and divide numbers by 10 and 100 Use doubling and halving as effective mental strategies for problem-solving Understand and explain multiplication and division rules related to 10 and 100

Success Criteria

Explain how multiplying or dividing by 10 and 100 shifts digits and changes place value Use doubling and halving strategies to simplify mental multiplication and division Solve multiplication and division problems mentally involving 10 and 100 Discuss and reflect on problem-solving methods with peers

Warm-up Challenge

Quick mental maths questions 5 × 10 = ? 240 ÷ 10 = ? What happens to digits when you multiply by 100? Use mini whiteboards to show answers

Place Value Magic: Multiplying by 10 and 100

Mental Maths Strategies

{"left":"Multiplying by 10: Move digits one place left OR add a zero to the end\nMultiplying by 100: Move digits two places left OR add two zeros to the end\nDividing by 10: Move digits one place right OR remove a zero from the end","right":"Dividing by 100: Move digits two places right OR remove two zeros from the end\nDoubling Strategy: Double the number, then adjust\nHalving Strategy: Halve the number, then adjust"}

Partner Practice Time

Work in pairs to solve these problems mentally: 350 × 10 2,400 ÷ 100 16 × 100 640 ÷ 10 Discuss your strategies with your partner Be ready to share your thinking!

Reflection and Next Steps

What mental strategy helped you most today? How did you know where to move the digits? Which problems were easiest? Which were trickiest? How will these strategies help you in everyday maths?